Unusual Illustration of Richter Transformation in Chronic Lymphocytic Leukemia on FDG PET/CT

A man with history of chronic lymphocytic leukemia (CLL) in remission had multiple rapidly growing lumps in recent 2 months. FDG PET/CT demonstrated disseminated FDG-avid nodal and extranodal lesions including those in unusual locations such as the nasopharynx, salivary glands, lungs, gastric wall, peritoneum, bones, and muscles. Subsequent biopsy of the right axillary mass showed absolute lymphocytosis with focus of large B-cell lymphoma. Flow cytometric immunophenotyping demonstrated κ-restricted CLL and B-cell lymphoma, consistent with Richter transformation of CLL. FDG PET/CT images of this case illustrated the most severe and most disseminated nodal and extranodal involvements of Richter transformation in CLL.